SANTA BARBARA COUNTY, Calif. -

California Highway Patrol officers are investigating a crash involving a horse trailer that overturned in Santa Barbara County.

Investigators say the driver was working for a professional horse transport company and was behind the wheel of a 3500 Dodge truck trailer designed to carry seven horses. However, 8 horses were inside the trailer at the time of the crash.

The CHP says the man was unable to negotiate a tight curve on Old San Marcos Road south of State Route 154 and overturned just after 5:30 a.m. on Friday.

The horses were thrown against the side of the trailer. The driver tried to remove the horses until help arrived. CHP officers, deputies from the Santa Barbara County Sheriff's Department, Santa Barbara Animal Services and the Santa Barbara Humane Society helped with the rescue and extrication of the animals. 

Three veterinarians from Santa Barbara also arrived on scene to treat the injured horses. One horse died and another had to be euthanized. Five horses were taken to Alamo Pintado Equine Medical Center in Santa Ynez. Their conditions are unknown. One horse was able to walk into its stable with minor injuries.

The driver is identified as 54-year-old Mathew Gillespie, from Arizona. He was not hurt in the accident.  Investigators say alcohol or drugs are not a factor in the crash.

2100 N San Marcos Rd, Santa Barbara, CA 93111